海洋工程高抗冻粉煤灰泵送混凝土研究

目的 为研制严寒地区海洋工程普通强度等级高抗冻粉煤灰泵送混凝土，提高该地区混凝土的高抗冻性．方法 采取试验的方法分析了粉煤灰含碳量对引气组分掺量的影响，研究适应粉煤灰混凝土的新型引气剂，测试评价了粉煤灰混凝土泵送前和泵送后的含气量差异，研制了普通强度等级(C30，C40)高耐海水冻融的混凝土，并应用与严寒地区的港口和沿海大桥工程．结果 研究表明，对于普通引气剂，粉煤灰含碳量严重影响了混凝土的含气量，当含碳量达到6％时，满足同种含气量，引气剂的掺量将提升到5倍以上。泵送施工过程中，混凝土含气量损失也是很显著的，配制高耐海水冻融的粉煤灰混凝土，必须研究专用的引气剂，同时，必须按泵送后的含气量设计混凝土．结论 高耐海水冻融的普通强度等级的粉煤灰泵送混凝土泵送后的含气量应在5％以上．否则，当混凝土的抗海水冻融指标虽然满足标准要求，但混凝土试件上已显示出冻害损伤的特征．

Research of High Resistant Freezing Fly Ash Pumping Concrete in Ocean Engineering

If ordinary strength fly ash pumping concrete can be used for ocean engineering in chilling areas,its properties will be improved greatly.In this paper,the effect of concrete air amount with Fly ash ignition loss is tested and analyzed,a new air entraining agent for fly ash concrete is exploited,and difference of fly ash concrete before and after pumping are tested.High resistant freezing ordinary strength fly ash pumping concrete is studied,and it is applied to harbor engineering and bridge along the ocean.The result shows that,for common air entraining agent,the effect of concrete air amount by fly ash ignition loss is notable.If ignition loss is high than 6%,for make the same air amount,air-entraining agent will need 5 times amount,and the loss of concrete air amount is very notability in construction.Thus high resistant freezing ordinary strength fly ash pumping concrete needs special air entraining agent.For make up ordinary strength fly ash pumping concrete having high resistant freezing with seawater,as a controlling index,air amount of concrete after pumping is higher than 5%,otherwise the freezing breakage characteristics of concrete test specimen is notable.